• Bert Quin

The History and Development of Liquid Fertilisers in New Zealand

Liquid fertilisers started to proliferate in New Zealand in the 1970s. Most of these were dilute extracts of seaweed or fish by-products, often augmented with small amounts of inorganic fertiliser NPK. Almost invariably they relied on unproven claims of massively greater nutrient efficiency than solid fertilisers, and the presence of various ‘growth stimulants’, to distract attention from the almost invariably miniscule amounts of nutrient being applied at the ‘recommended’ rates. Profit margins were of course considerable.


The claim by Maxicrop in a national TV advertising campaign in 1985 that “3 pints will feed an acre” lead to public criticism of the company’s claims, and a scientifically simplistic statement by MAF scientist Dr Doug Edmeades on a ‘Fair Go’ TV program that the product ‘did not work’ by a scientist from the MAF’s Agricultural Research Division, resulted in an $11 million defamation law suit by Maxicrop. Dr Bert Quin, at the time Chief Scientist for Soil Fertility at the Division’s Ruakura Research Centre, was appointed as Scientific Advisor to Don Matheson QC, who successfully defended the year-long case for the MAF. Dr Edmeades later joined the defense team to prepare MAF witnesses.

An unfortunate by-product of this case is that the merit and potential of any form of liquid fertiliser was downgraded massively in the minds of most fertiliser researchers and applicators in New Zealand, with the result that very positive developments being made in other countries, with high-solids suspension fertilisers especially, created little or no immediate interest in New Zealand.

High-solids Fluids

However, the last few years have seen a marked resurgence in interest, lead initially by the use of helicopters in the North Island and fixed-wing aircraft in the South Island, to provide reasonably-competitive, near-sustaining rates of nutrients and fine lime, in high-solids suspension or ‘fluid’ form, to hill country. This resurgence in recent years has been assisted by evidence – now proven in scientific studies – that fluidised urea, to which urease inhibitor has been added, is vastly (typically two and a half times) more efficient in producing extra dry matter (DM) per unit N than is granular urea.

Two groundspreading technology companies, one of which (Quinspread Technologies Limited), Bert Quin had a commercial interest in, have introduced new technology that allows urea and other fertilisers to be converted on–truck into concentrated fluids, during the spreading operation, resulting in far greater pasture growth responses per kg N applied.. However, very high capital and maintenance costs of the equipment combined with narrow (10m) swath widths, have greatly restricted the uptake of this technology. Dr Quin left Quinspread Technologies in 2013 to pursue his dream of greatly reducing the cost of improving the efficiency of urea. The assets of this company are now owned by entities associated with N.T. Wealleans Ltd of Hinuera, Waikato. Dr Quin’s endeavours have since resulted in the development of ONEsystem®.

Questionable Practices Continue

Recent market entry by new companies  heavily promoting products that provide little in the way of vital nutrients to replace losses –  at the ‘recommended’ rates of application – has caused considerable concern. For the farmer with little fertiliser and soil fertility knowledge, it can be very difficult to see through a sophisticated syrup of ‘healthy soil biology’ jargon and product performance claims that are unsupported by any credible evidence. Just as concerning however, is the scaremongering tactics of some so-called ‘independent experts’ who prefer to blindly promote obselete products and practises rather than do any new research themselves.